316 LAVOISIER. 



time imparted to him, and of his own incredulity until 

 he repeated the experiment and convinced himself. 



It seems, therefore, quite certain, that in this case, 

 as in that of oxygen, M. Lavoisier's intrusion is clearly 

 proved; that he performed an experiment which another 

 had before, to his knowledge, contrived and made ; that 

 he drew a conclusion from it, in substance the same 

 with the conclusion which others had drawn, and which 

 he had been apprized of, before he either produced the 

 experiment or reasoned upon its results ; that he related 

 the whole, both in his ' Memoirs,' and in his ' Elements,' 

 as if he had been the author of the discovery ; and 

 that he only told a part of the communication pre- 

 viously made to him, leaving out if he did not suppress, 

 the most important portion of the statement, the theory 

 of the process. 



It is on the other hand certain, that from having 

 abandoned the phlogiston hypothesis, his theory of the 

 experiment was more distinctly and accurately given 

 than it had been by former reasoners who were ham- 

 pered with the errors of that doctrine : although in the 

 popular language at the time, the composition and de- 

 composition of water was always spoken of as the 

 discovery that had been made. We must further allow, 

 that M. Lavoisier added a valuable experiment to the 

 synthetical process of Priestley and Cavendish, the 

 analysis of water by passing its vapour or steam over 

 hot iron filings, and finding that the oxygen calcined 

 the metal, while the other constituent part escaped in 

 the form of inflammable air ; an experiment of excel- 

 lent use after the more crucial trial of the composition 

 had been made, but wholly inconclusive had it stood 

 by itself* 



* An admirable experiment similar to Mr. Cavendish's was performed 

 in June, 1783, by M. Monge, at Mezieres. The account of it is given in 

 the volume for 1783 ; and the author mentions in a note both Lavoisier 

 and Cavendish's experiments, stating that they were performed on a 

 smaller scale. 



